This proposal represents a request to support participation in Acute Leukemia Cooperative Group B. This cooperative research is devoted to the investigation of chemotherapeutic approaches to acute leukemia and other human neoplastic diseases. Significant palliation and prolongation of survival has been achieved and contributions have been made in clinical pharmacology. However, the real objective of these studies is the eradication of neoplastic disease in the patient studied. Studies are being designed to reflect an increasing intensity of attack on the neoplastic process. The group approach permits the exploration in series of reasonable size of any promising leads in chemotherapy. These leads or new approaches are often suggested by the results of the Group's own work in clinical oncology. Thus, a completed protocol often suggests the new avenues to be explored in new protocols. In addition, protocols are designed to exploit maximally clinical or conceptual advances made in experimental animals. The principal investigator has been involved in this project since 1963. She has chaired studies in childhood solid tumor and acute leukemias. Dr. Nyhan has served as the Chairman of the Childhood Solid Tumor Subcommittee and is currently the Chairman of the Membership Committee. We have continued to be a major contributor of patients to Group studies.